Reciprocating motion device



May 25, 1931 H. E. DELWN- 1 2,08 ,7 6

RECIPROCATING MOTION DEVICE Filed June 6, 1936 3 Sheets-Sheet 1 I a Z 12 lnveni'on flan E- Delv'z'n,

MM An a.

y H. E. DELVlN 2,081,796

RECIPROCATING MOTION DEVICE Filed June 6, 1956 3 Sheets-Sheet 2 In weni'or 29 .Harz E Deli/in W WMM May 25, 1937.-

HIE. DELVIN RECIPROCATING MOTION DEVICE Filed June 6, 1936 3 Sheets-Sheet 3 r2 L7. Deli/in Patented May 25, 1937 UNITED, STATES PATENT QFFIQE 2,081,796 REOIPROCATING MOTION DEVICE Hart E. Delvin, Gary, Ind.

Application June 6, 1936, Serial No. 83,865

11 Claims.

bination of reciprocation with rotation; to pro vide a mechanism of this kind that is of compact form, especially adapted to be motor driven and fully automatic and sturdy; and to provide such mechanism in an improved form applicable for use in a wide range of devices as will be apparent from the following description.

This application is in part a continuation and amplification of the disclosure of certain parts of the subject matter of my co-pending application, Serial No. 715,196 filed March 12, 1934,

which describes and claims a specific embodiment of this invention in a pump-operating mechanism but makes no claim to the operating mechanism per se which is the subject of the present application. I

In the accompanying drawings, I have illustrated a specific embodiment of the invention as applied to mixing devices, wherein an agitator shaft is caused to rotate rapidly and at the same time reciprocate slowly in an axial direction.

Figure l of the drawings is a side elevation, partly in section, of the complete mixer.

' Fig. 2 is a section taken on the line 22 of Fig. 1 and showing on a larger scale the mechanism for converting the rotary motion of the motor into a simultaneous rotary and reciprocatory motion of the agitator shaft.

Fig. 3 is a section taken on the line 3-3 of Fig. 2.

Fig. 4 is a side elevation of the plunger illustrating the form and arrangement of the peripheral screw threads and guide means whereby the reciprocatory movement of the plunger is accomplished.

Fig. 5 is a detail of the camming arm that reverses the direction of movement of the plunger at the lower end of its stroke.

Fig. 6 is a diagrammatic detail showing the relation of the camming arm with the pin at the The present invention contemplates the use of cooperating mutually threaded concentric cylindrical members having a novel arrangement of screw threads and guides for producing a relative reciprocatory motion through the relative rotation of these members.

In the form shown in the drawings, the motor is housed within a cylindrical casing I and its drive shaft 2 is connected by a train of spur gears 3 with a shaft disposed axially within a hollow cylindrical member 5 extending parallel to the drive shaft 2 along one side of the housing I, and preferably directly opposite to the handle 6 whereby the operator may manipulate the mixer.

The cylinder 5 has cut or otherwise formed on its inner periphery what might be termed a square or broad-crested helical thread, or set of threads "l, having wide grooves 8 between its convolutions and having narrow-crested or V-shaped helical threads 9 cut or otherwise formed into and across the crests of the threads I. The pitches of the threads l and 9 are oppositely directed; that is to say. one is right-handed and the other is left-handed. They should differ in thread-sectional shape but they may or may not be of the same pitch length. In the form shown the unit pitch of the V-threads 9 is less than that of the square threads 7 and the cooperating plunger l accordingly travels faster in one direction than in the other of its vertical stroke.

A worm-like plunger member Ill slidably fits the shaft 4 and is held in fixed angular relation thereto by means of a spline H so that it rotates with the shaft 4.

The external periphery of the member ID is provided with broad-crested threads I2 of the same pitch as the threads 1 of the cylinder, so that its threads it are adapted to mate with the threads 1. Likewise, the threads l2 have out over them V-shaped threads I3 of proper pitch and shaped to mate with the V-threads 9 of the cylinder. In each case the broad-crested or square threads and the narrow-crested or V-threads should all be of approximately the same height so that the plunger member may follow either set of threads in its rotation within the cylinder without interference by the other set of threads.

The plunger member lil has a bar or slide member l4 mounted within a way it that extends transversely through the plunger and one end it of this bar is provided with one or more threads fitting only the threaded grooves of the broad-crested threads l of the cylinder so that this end of the bar l4 serves as a guide memher to compel the plunger to follow the broadcrested threads I of the cylinder.

The opposite end I! of the bar M is threaded to fit only the narrow-crested or V-threads 9 of the cylinder. This end I! of the bar It should preferably be of sufiicient thickness so that its threads will somewhat more than span the thread grooves 8 and thus serve as guide means for compelling the plunger member to follow the narrow-crested grooves only.

It will thus be seen that with continuous rotation in one direction of the shaft 4 and the plunger, the plunger will travel downward or upward in the cylinder according to the position of the bar [4 controlling the guide means 15 and IT.

The position of the bar I4 is in turn controlled by means of a cam I8 carried by an arbor 19 extending through and journaled in the plunger l9. Abutments 2i! and 2| are formed at the ends of a cam aperture in the slide M to cooperate with the cam. Cam arms 22 and 23, fast on the respective ends of arbor H), are positioned to engage pins or other abutments 24 and 25 at the upper and lower ends of the cylinder respectively and through the action of the cam l8 operate to reverse the direction of movement of the plunger at the ends of the stroke by retracting one and projecting the other of the guide means It and H as the case requires.

Stud bolts 26 secure the head 21 to the plunger and this head carries a quill shaft 28 which extends outwardly from a lower head 29 of the cylinder 5 and carries at its lower end an agitator 3!! which, in the form shown, is a twobladed propeller having its hub shaped to form a closure cap St for the lower end of the quill shaft 28.

The cap 3| is provided with a ball 32 that snaps into a spring socket 33 housed within the lower end of the quill shaft and studs 34 secure the head 38 against rotation independent of the quill.

In operation the motor may be controlled by any appropriate form of circuit closer, not shown, and drives the shaft 4 in one direction continuously. The plunger rotates with the shaft 6, due to their splined relation and if the guide It is projected to its operative position, as in Fig. 2, then clockwise rotation of the shaft t would cause the plunger ID to travel downward under the influence of the broad-crested threads I.

When the plunger approaches the lower end of the cylinder, the arm 23 engages the abutment 25 and rotates the cam I8 until the guide it has been fully retracted and the guide I! has securely engaged its corresponding threads; whereupon the continuous rotation of the plunger it causes it to follow the left-hand or narrowcrested threads and travel upward in the cylinder.

The abutments 24 and 25 may be so placed that each will rotate the cam 180 in one direction or they may be placed as shown in Figs. 2 and 5, so that one of them rotates the cam in one direction through some definite angle less than 180 and the other reverses the motion of the cam. The latter arrangement is preferred because it prevents any possibility of overthrow of the cam. In Fig. the arrow 35 indicates the path of the cam arbor about the axis of the plunger.

The bar I is held in either of its limiting posi tions by friction means, as for example, a disc 35 and spring 36, shown in Fig. 2.

Although but one specific embodiment of this invention is herein shown and described, it is to be understood that numerous details may be altered or omitted without departing from the spirit of the invention as defined by the following claims.

I claim:

1. In a reciprocating drive mechanism an internally threaded member, an externally threaded member, each of said members having thereon a or ad crested thread and a narrow crested thread of different pitch formed on the crests of said broad crested thread, the respective threads on said members being formed to mate with each other, and relatively shiftable thread engaging means on one of said threaded mem- 3 r selectively holding one or the other set 1 mating threads operative to produce axial movement of one of said members through the relative rotation of said members.

2. In a reciprocating drive mechanism, an internally threaded member, an externally threaded member, each of said members having thereon a broad crested thread and a narrow crested thread of different pitch formed on the crests of said broad crested thread, the respective threads on said members being formed to mate with each other, relatively shiftable thread engaging means on one of said threaded members for selectively holding one or the other set of said mating threads operative to produce axial movement of one of said members through the relative rotation of said members, and means on the other of said members operative through such relative rotation to shift said shiftable means for reversing such axial movement.

3. A reciprocating rotary drive mechanism comprising a cylinder having a broad crested spiral thread on its inner wall and having a narrow crested spiral thread of reversed direction on the crests of said broad crested thread, a plunger fitted within said cylinder and having two sets of threads on its periphery respectively mating with different ones of said cylinder threads, guide means coacting with said plunger and alternately shiftable into and out of engagement with said threads respectively, an axial drive shaft for said plunger, means for rotating said shaft, and reversing mechanism for shifting said guide means from one of said cylinder threads to the other at the opposite ends of said cylinder respectively.

4. A reciprocating drive mechanism comprising a cylinder having a broad crested square spiral thread cut on its inner wall and having a narrow crested spiral thread of reversed direction cut on the crests of said square thread, a plunger fitted within said cylinder and having two sets of threads on its periphery respectively mating with the threads on said cylinder, guide means on said plunger having parts respectively mating with different ones of said two sets of cylinder threads and alternately shiftable into and out of engagement with their respective threads, an axial shaf splined to said plunger, motor means for rotating said shaft, and reversing mechanism for shifting said guide means from one set of said cylinder threads to the other at the opposite ends of said cylinder respectively.

5. A reciprocating rotary drive mechanism comprising a cylinder having a broad crested spiral thread on its inner wall and having a narrow crested spiral thread of reversed direction on the crests of said broad crested thread, a plunger fitted within said cylinder and having two sets of threads on its periphery respectively mating with different ones of said cylinder threads, guide means coacting with said plunger and alternately shiftable into and out of engagement with said threads respectively, an axial drive shaft for said plunger, means for rotating said shaft, and camming means associated with said guide means, and elements at opposite ends of said cylinder coacting with said camming means to reverse said guide means through the rotary movement of said plunger.

6. In areciprocating drive mechanism, a cylinder, a broad crested helical thread on the inner surface of said cylinder, a V-thread of reverse pitch formed on the crests of said broad crested helical thread, a plunger having peripheral threads respectively mating with the threads on said cylinder, a bar slidable transversely on said plunger, opposite ends of said bar being shaped to engage and follow different ones of said cylinder threads respectively, means to shift said bar from one thread to the other at the ends of said cylinder, and means to rotate said plunger continuously in one direction whereby said plunger is caused to move reciprocatively in its axial direction.

7. In a reciprocating rotary drive mechanism, a cylinder provided with right and left-hand screw threads on its inner wall surface, a plunger having right and left-hand threads on its periphery shaped to mate with the corresponding threads of said cylinder, a cross bar mounted to slide transversely on said plunger and shaped to engage at its opposite ends with one or the other of the threads on said cylinder respectively, a cam to move said bar into engagement with either the right or left-hand threads in the cylinder, a shaft for said cam extending through said piston and having arms at its opposite ends, and projections at opposite ends of said cylinder to engage said arms and actuate said cam to shift said cross-bar from one of said threads to the other when said plunger reaches the ends of its stroke.

8. In a reciprocating rotary drive mechanism, a rotatable spindle, a plunger splined thereto and slidably disposed thereon, a cylinder having threads on the wall of predetermined pitch, a bar transversely slidable on the plunger and having one end arranged to engage said threads for moving the plunger in one direction, said cylinder also having threads of reversed pitch and said bar having threads on the opposite end arranged to engage the last-named threads on the cylinder for moving the plunger in the opposite direction, and means for shifting the bar from its engagement with one set of threads to engage the other set at each end of the cylinder.

9. In a reciprocating rotary drive mechanism, a rotatable spindle, a plunger splined thereto and slidably disposed thereon, a cylinder having threads on its Walls of predetermined pitch, a bar transversely slidable on the plunger and arranged at one end to engage said threads for moving the plunger in one direction, said cylinder also having threads of reversed pitch and said bar having threads on the opposite end arranged to engage the last-named threads on the cylinder for moving the plunger in the opposite direction, means for shifting the bar from its engagement with one set of threads to engage the other set at each end of the cylinder, said last-named means comprising a rotatable cam and a pair of associated arms carried by the plunger, and means at each end of the cylinder and adapted to engage one of said arms respectively for actuating the cam.

10. In a reciprocating drive mechanism, a rotatable spindle, a plunger splined thereon, a bar transversely slidable on said plunger, and a cylinder coacting with said plunger, means on the walls of said cylinder adapted to be engaged by one end of the bar for causing a movement of the plunger in one direction, and means on the walls of said cylinder engaged by the other end of the bar causing movement in the reverse direction.

11. In a reciprocating drive mechanism an internally threaded member, an externally threaded member, each of said members having thereon a right-hand thread and a left-hand thread formed one over the other and substantially co-extensive axially, the respective threads on said members being formed to mate with each other, and relatively shiftable thread engaging means on one of said threaded members for selectively holding one or the other set of said mating threads operative to produce axial movement of one of said members through the relative rotation of said members.

HART E. DELVIN. 

